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Sight and blindness in the same person: Gating in the visual system.
Hans Strasburger1, Bruno Waldvogel2
1Institute of Medical Psychology, Ludwig Maximilian University, Munich, Germany.
Psych Journal
|October 16, 2015
Summary
Dissociative identity disorder (DID) can cause psychogenic blindness, where vision loss is linked to personality states. Psychotherapy helped a patient regain sight, demonstrating top-down modulation of the visual pathway.
Area of Science:
- Neuroscience
- Psychiatry
- Ophthalmology
Background:
- Dissociative identity disorder (DID) is a complex mental health condition.
- Psychogenic blindness, or vision loss without organic cause, can be associated with DID.
- A patient with DID experienced 15 years of misdiagnosed cortical blindness.
Observation:
- The patient gradually regained vision during psychotherapeutic treatment.
- Initially, only specific personality states regained vision, while others remained blind.
- Electrophysiological measurements (visual evoked potentials - VEPs) confirmed absent VEPs in blind states and normal VEPs in seeing states.
Findings:
- Visual evoked potentials (VEPs) did not differentiate psychogenic blindness from organic visual pathway disruption.
- The findings suggest psychogenic blindness suppresses visual information at an early neural stage.
- Rapid shifts in vision occurred, correlating with switches between personality states.
Implications:
- Top-down modulation of the primary visual pathway, potentially at the thalamus, is hypothesized as the neural basis for psychogenic blindness.
- Psychotherapy can be effective in treating psychogenic blindness associated with DID.
- This case highlights the intricate connection between psychological states and sensory perception.
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